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Discussion Starter #1
Okay... so my sportsman ran great a year ago before parked.... carb was already bad, ordered a new one, and no more backfires... but I can’t get it to start and idle or run. When I turn the key it will turn over just fine and then I get a lot of sputtering... the lower the float level, the more sputtering, the higher the float level, the less sputter but more with choke.... if I give any throttle at all it stops sputtering. Yes I have tried the float to be level with the body, no good.
Please help...

Thank you all in advance..
 

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Discussion Starter #3
Have you installed new spark plugs?
Yes, at least 3 times because I thought that was it... It will try to start sometimes, sometimes nothing, when it tries tho I can’t even let off key or it quits.
 

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Discussion Starter #4
Yes, at least 3 times because I thought that was it... It will try to start sometimes, sometimes nothing, when it tries tho I can’t even let off key or it quits.
I think it’s carburetor issues but I can’t even get anything with starting fluid... I’m completely lost here..
 

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Discussion Starter #5
I think it’s carburetor issues but I can’t even get anything with starting fluid... I’m completely lost here..
I also had an issue before this with the choke, my carburetor came with two different screws, I had the wrong one in and whenever it started I could idle great but if I gave any throttle without a bit of choke to get going I would get backfires all around, carburetor backfires, exhaust backfires. I put the correct cable and now this.
 

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Discussion Starter #6
Okay so I checked my plugs... they keeps turning black and fouled out every time...
 

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It could be an ignition issue - while the black plugs does point to a carb issue, a weak spark or late could cause improper ignition and cold combustion - just a possibility worth mentioning
 

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Discussion Starter #8
I
It could be an ignition issue - while the black plugs does point to a carb issue, a weak spark or late could cause improper ignition and cold combustion - just a possibility worth mentioning
I am going to try new plugs... I just installed a brand new rmstator CDI upgrade... the spark is good
 

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Discussion Starter #9
I

I am going to try new plugs... I just installed a brand new rmstator CDI upgrade... the spark is good
I

I am going to try new plugs... I just installed a brand new rmstator CDI upgrade... the spark is good
I put new plugs... fired right up, idles great, give any throttle it pops and backfires, with choke I can rev fully and turn choke off and be fine.. but the exhaust is red hot on any throttle.
 

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Discussion Starter #12
Carb needs serviced or replaced or you might have a vacuum leak - it needs checked by a competent mechanic
Okay I’ll look into it, what carburetor would you recommend? I just put in a cheapish one but I think it’s faulty because I have good flow from the pump...
 

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I recommend a Mikuni BST34 properly calibrated, but since it is discontinued you will have to rebuild the original carb, or get a used on and rebuild it.
 

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Discussion Starter #14
I recommend a Mikuni BST34 properly calibrated, but since it is discontinued you will have to rebuild the original carb, or get a used on and rebuild it.
Okay... the jet that is the biggest is stuck and spinning freely I can’t get it out...
 

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The needle jet (#6 in the schematic below) is blanch cut on the bottom end and wedges against the plastic jet block (#9) to prevent turning - it was at some time over tightened or the wrong thread pitch main jet was installed causing this problem. If I was working on it, I would use an Easy Out broken screw removal tool inserted into the needle jet from the venturi side to hold it to allow enough torque on the main jet to remove it. Once the main jet is removed, push the needle jet out of the jet block and inspect the jet block for a crack and that the wedge inside that the needle jet wedges against is not damaged. If the jet block is damaged, you will need a replacement carb to get the part as it is NLA from Polaris. Or you can get creative and adapt a different carb to take the place of the damaged one or get another Chinese carb and hope for the best. If the jet block is usable, get a new needle jet (part # 3131363 @ $25) as the one held with the Easy Out is now junk.

137799
 

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Discussion Starter #16
The needle jet (#6 in the schematic below) is blanch cut on the bottom end and wedges against the plastic jet block (#9) to prevent turning - it was at some time over tightened or the wrong thread pitch main jet was installed causing this problem. If I was working on it, I would use an Easy Out broken screw removal tool inserted into the needle jet from the venturi side to hold it to allow enough torque on the main jet to remove it. Once the main jet is removed, push the needle jet out of the jet block and inspect the jet block for a crack and that the wedge inside that the needle jet wedges against is not damaged. If the jet block is damaged, you will need a replacement carb to get the part as it is NLA from Polaris. Or you can get creative and adapt a different carb to take the place of the damaged one or get another Chinese carb and hope for the best. If the jet block is usable, get a new needle jet (part # 3131363 @ $25) as the one held with the Easy Out is now junk.

View attachment 137799
When I try to start, it will sometime try but mostly it will just stop turning and blow white smoke out of the carb an then turn again...
 
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